Perhaps you should try some spelling variations:
day nhanh » day thanh, duy nhanh, dac nhan
ban hanh » ban hang
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
ty nang » ky nang, ty xang, ty hang
va cam » va cham, va cac, va cai
di cua » dai cua, doi cua, de cua
va cao » va cac, va co, va dao
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ty nang x hoi. hieu ((va cam) OR (va cao)) thuc ((ban hanh) or (day nhanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty nang x hoi. hieu ((va cam) OR (va cao)) thuc ((ban hanh) OR (day nhanh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty nang x hoi. hieu ((va cam) OR (va cao)) thuc ((ban hanh) or (day nhanh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang x hoi. hieu ((va cam) OR (va cao)) thuc ((ban hanh) or (day nhanh)) di cua tre*.